VITESSE VSC7125QU

VITESSE
SEMICONDUCTOR CORPORATION
Data Sheet
1.0625 Gbits/sec Fibre
Channel Transceiver
VSC7125
Features
• ANSI X3T11 Fibre Channel Compatible
1.0625 Gbps Full-duplex Transceiver
• 106.25 MHz TTL Reference Clock
• 10 Bit TTL Interface for Transmit and
Receive Data
• Suitable for Both Coaxial and Optical
Link Applications
• Monolithic Clock Synthesis and Clock
Recovery - No External Components
• 64 Pin, 10mm or 14mm PQFP
• Low Power Operation - 650 mW
• Single +3.3V Power Supply
General Description
The VSC7125 is a full-speed Fibre Channel Transceiver optimized for Disk Drive and other space constrained applications. It accepts 10-bit 8B/10B encoded transmit data, latches it on the rising edge of REFCLK
and serializes it onto the TX PECL differential outputs at a baud rate which is ten times the REFCLK frequency.
The VSC7125 also samples serial receive data on the RX PECL differential inputs, recovers the clock and data,
deserializes it onto the 10-bit receive data bus, outputs two recovered clocks at one twentieth of the incoming
baud rate and detects Fibre Channel “Comma” characters. The VSC7125 contains on-chip PLL circuitry for
synthesis of the baud-rate transmit clock, and extraction of the clock from the received serial stream. These circuits are fully monolithic and require no external components.
VSC7125 Block Diagram
EWRAP
R0:9
10
Serial to
Parallel
QD
÷ 10
RCLK
Retimed
Data
QD
Clock
Recovery
2:1
RX+
RX-
Recovered
Clock
÷ 20
RCLKN
Resync
Frame
Logic
Comma
Detect
COM_DET
EN_CDET
10
T0:9
DQ
Parallel
to Serial
Serial Data
DQ
TX+
TX-
Synthesized
Clock
REFCLK
G52121-0, Rev. 4.1
4/23/98
PLL Clock
Multiply
 VITESSE SEMICONDUCTOR CORPORATION
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Page 1
VITESSE
SEMICONDUCTOR CORPORATION
Data Sheet
1.0625 Gbits/sec Fibre
Channel Transceiver
VSC7125
Functional Description
Clock Synthesizer
The VSC7125 clock synthesizer multiplies the reference frequency provided on the REFCLK pin by 10 to
achieve a baud rate clock at nominally 1.0625 GHz. The clock synthesizer contains a fully monolithic PLL
which does not require any external components.
Serializer
The VSC7125 accepts TTL input data as a parallel 10 bit character on the T0:9 bus which is latched into the
input latch on the rising edge of REFCLK. This data will be serialized and transmitted on the TX PECL differential outputs at a baud rate of ten times the frequency of the REFCLK input, with bit T0 transmitted first. User
data should be encoded for transmission using the 8B/10B block code described in the Fibre Channel specification, or an equivalent, edge rich, DC-balanced code.
Transmission Character Interface
In Fibre Channel, an encoded byte is 10 bits and is referred to as a transmission character. The 10 bit interface on the VSC7125 corresponds to a transmission character. This mapping is illustrated below.
Figure 1: Transmission Order and Mapping to Fibre Channel Character
Parallel Data Bits
T9
T8
T7
T6
T5
T4
T3
T2
T1
T0
8B/10B Bit Position
j
h
g
f
i
e
d
c
b
a
Comma Character
X
X
X
1
1
1
1
1
0
0
Last Data Bit Transmitted
First Data Bit Transmitted
Clock Recovery
The VSC7125 accepts differential high speed serial inputs on the RX+/RX- pins, extracts the clock and
retimes the data. The serial bit stream should be encoded to provide DC balance and limited run length by a
Fibre Channel compatible 8B/10B transmitter or equivalent. The VSC7125 clock recovery circuitry is completely monolithic and requires no external components. For proper operation, the baud rate of the data stream
to be recovered should be within 0.01% of ten times the REFCLK frequency. For example if the REFCLK used
is 106.25MHz, then the incoming serial baud rate must be 1.0625 gigabaud +0.01%.
Deserializer
The retimed serial bit stream is converted into a 10-bit parallel output character. The VSC7125 provides
complementary TTL recovered clocks, RCLK and RCLKN, which are at one twentieth of the serial baud rate.
This architecture is designed to simplify demultiplexing of the 10-bit data characters into a 20-bit halfword in
the downstream controller chip. The clocks are generated by dividing down the high-speed clock which is phase
locked to the serial data. The serial data is retimed by the internal high-speed clock, and deserialized. The
Page 2
 VITESSE SEMICONDUCTOR CORPORATION
741 Calle Plano, Camarillo, CA 93012 • 805/388-3700 • FAX: 805/987-5896
G52121-0, Rev. 4.1
4/23/98
VITESSE
SEMICONDUCTOR CORPORATION
Data Sheet
VSC7125
1.0625 Gbits/sec Fibre
Channel Transceiver
resulting parallel data will be captured by the adjoining protocol logic on the rising edges of RCLK and
RCLKN. In order to maximize the setup and hold times available at this interface, the parallel data is loaded
into the output register at a point nominally midway between the transition edges of RCLK and RCLKN.
If serial input data is not present, or does not meet the required baud rate, the VSC7125 will continue to
produce a recovered clock so that downstream logic may continue to function. The RCLK and RCLKN output
frequency under these circumstances may differ from their expected frequency by no more than +1%.
Word Alignment
The VSC7125 provides 7-bit Fibre Channel comma character recognition and data word alignment. Word
synchronization is enabled by asserting EN_CDET HIGH. When synchronization is enabled, the VSC7125 constantly examines the serial data for the presence of the Fibre Channel “comma” character. This pattern is
“0011111XXX”, where the leading zero corresponds to the first bit received. The comma sequence is not contained in any normal 8B/10B coded data character or pair of adjacent characters. It occurs only within special
characters, known as K28.1, K28.5 and K28.7, which is defined specifically for synchronization in Fibre Channel systems. Improper alignment of the comma character is defined as any of the following conditions:
1) The comma is not aligned within the 10-bit transmission character such that T0...T6 = “0011111”
2) The comma straddles the boundary between two 10-bit transmission characters.
3) The comma is properly aligned but occurs in the received character presented during the rising edge of
RCLK rather than RCLKN.
When EN_CDET is HIGH and an improperly aligned comma is encountered, the internal data is shifted in
such a manner that the comma character is aligned properly in R0:9. This results in proper character and halfword alignment. When the parallel data alignment changes in response to an improperly aligned comma pattern,
some data which would have been presented on the parallel output port may be lost. However, the synchronization character and subsequent data will be output correctly and properly aligned. When EN_CDET is LOW, the
current alignment of the serial data is maintained indefinitely, regardless of data pattern.
On encountering a comma character, COM_DET is driven HIGH to inform the user that realignment of the
parallel data field may have occurred. The COM_DET pulse is presented simultaneously with the comma character and has a duration equal to the data, or half of an RCLK period. The COM_DET signal is timed such that
it can be captured by the adjoining protocol logic on the rising edge of RCLKN. Functional waveforms for synchronization are given in Figure 2 and Figure 3. Figure 2 shows the case when a comma character is detected
and no phase adjustment is necessary. It illustrates the position of the COM_DET pulse in relation to the comma
character on R0:9. Figure 3 shows the case where the K28.5 is detected, but it is out of phase and a change in
the output data alignment is required. Note that up to three characters prior to the comma character may be corrupted by the realignment process.
G52121-0, Rev. 4.1
4/23/98
 VITESSE SEMICONDUCTOR CORPORATION
741 Calle Plano, Camarillo, CA 93012 • 805/388-3700 • FAX: 805/987-5896
Page 3
VITESSE
SEMICONDUCTOR CORPORATION
Data Sheet
1.0625 Gbits/sec Fibre
Channel Transceiver
VSC7125
Figure 2: Detection of a Properly Aligned Comma Character
RCLK
RCLKN
COM_DET
R0:9
K28.5
TChar
TChar
TChar
TChar: 10 bit Transmission Character
Figure 3: Detection and Resynchronization of an Improperly Aligned Comma
Receiving Two Consecutive K28.5+TChar Transmission Words
RCLK
RCLKN
COM_DET
K28.5
R0:9
TChar
TChar
TChar
K28.5
TChar
Potentially Corrupted
Page 4
 VITESSE SEMICONDUCTOR CORPORATION
741 Calle Plano, Camarillo, CA 93012 • 805/388-3700 • FAX: 805/987-5896
G52121-0, Rev. 4.1
4/23/98
VITESSE
SEMICONDUCTOR CORPORATION
Data Sheet
1.0625 Gbits/sec Fibre
Channel Transceiver
VSC7125
Figure 4: Transmit Timing Waveforms
REFCLK
T2
T1
T0:9
10 Bit Data
Data Valid
Data Valid
Data Valid
AC Characteristics
Table 1: Transmit AC Characteristics
Parameters
Description
Min
Max
Units
T1
T0:9 Setup time to the rising
edge of REFCLK
1.5
—
ns.
T2
T0:9 hold time after the
rising edge of REFCLK
1.0
—
ns.
TX+/TX- rise and fall time
—
300
ps.
TSDR,TSDF
TLAT
Trj
TDJ
G52121-0, Rev. 4.1
4/23/98
Latency from rising edge of
11bc - 1ns
ns.
REFCLK to T0 appearing on
TX+/TXTransmitter Output Jitter Allocation
Serial data output random
—
20
ps.
jitter (RMS)
Serial data output
—
100
ps.
deterministic jitter (p-p)
Conditions
Measured between the valid
data level of T0:9 to the 1.4V
point of REFCLK
20% to 80%, 75 Ohm load to
Vss, Tested on a sample basis
bc = Bit clocks
ns = Nano second
RMS, tested on a sample basis
(refer to Figure 8)
Peak to peak, tested on a sample
basis (refer to Figure 8)
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Page 5
VITESSE
SEMICONDUCTOR CORPORATION
Data Sheet
1.0625 Gbits/sec Fibre
Channel Transceiver
VSC7125
Table 2: Receive AC Characteristics
Parameters
T1
T2
T3
Description
Data or COM_DET Valid
prior to RCLK/RCLKN
rise
Data or COM_DET Valid
after RCLK or RCLKN
rise
Deviation of RCLK
rising edge to RCLKN
rising edge delay from
nominal.
Min.
Max.
Units
4.0
—
ns.
3.0
—
ns.
-500
500
ps.
Nominal delay is 10 bit
times. Tested on sample
basis
-1.0
1.0
%
Whether or not locked to
serial data
ns.
f baud
- ± T3
delay = ------------10
T4
Deviation of RCLK,
RCLKN frequency from
nominal.
f REFCLK
- ± T4
f RCLK = ---------------------2
TR, TF
R0:9, COM_DET, RCLK,
RCLKN rise and fall time
—
2.4
Rlat
Latency from RX to R0:9
15bc + 2ns
34bc + 2ns
TLOCK
Data acquisition lock time
@ 1.0625Gb/s
—
2.4
Conditions
Measured between the
1.4V point of RCLK or
RCLKN and a valid level
of R0:9. All outputs
driving 10pF load.
Between Vil(max) and
Vih(min), into 10 pf. load.
bc = Bit clock
ns = Nano second
µs.
8B/10B IDLE pattern.
Tested on a sample basis
ps.
dBc, RMS for l0-12 Bit
Error Ratio Tested on a
sample basis
Receive Data Jitter Power
Receive Data
Jitter
1
------------------------------2 × BitTime
∫
—
40
PhaseNoise
100KHz
Note: Probability of recovery for data acquisition is 95% per section 5.3 of the FC-PH rev. 4.3.
Page 6
 VITESSE SEMICONDUCTOR CORPORATION
741 Calle Plano, Camarillo, CA 93012 • 805/388-3700 • FAX: 805/987-5896
G52121-0, Rev. 4.1
4/23/98
VITESSE
SEMICONDUCTOR CORPORATION
Data Sheet
1.0625 Gbits/sec Fibre
Channel Transceiver
VSC7125
Figure 5: Receive Timing Waveforms
T4
T3
RCLK
RCLKN
T2
T1
R0:9
Data Valid
Data Valid
Data Valid
Figure 6: REFCLK Timing Waveforms
TH
TL
Vih(min)
REFCLK
Vil(max)
Table 3: Reference Clock Requirements
Parameters
FR
FO
DC
TRCR,TRCF
REFCLK
Jitter
Description
Frequency Range
Frequency Offset
REFCLK duty cycle
REFCLK rise and fall time
REFCLK Jitter Power
5MHz
∫
PhaseNoise
Min
100
Max
110
Unit
s
MHz
Conditions
Range over which both transmit and
receive reference clocks on any link
may be centered
Maximum frequency offset between
transmit and receive reference clocks
on one link
-200
200
ppm.
30
70
%
—
2.0
ns.
—
2
ps.
dbc, RMS for FC compliant output
data jitter
ps.
dbc, RMS for 10-12 Bit Error Ratio
with zero length external path. Tested
on a sample basis
Measured at 1.5V
Between Vil(max) and Vih(min)
100Hz
REFCLK Jitter Power
REFCLK
Jitter
5MHz
∫
100Hz
G52121-0, Rev. 4.1
4/23/98
PhaseNoise
—
40
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VITESSE
SEMICONDUCTOR CORPORATION
Data Sheet
1.0625 Gbits/sec Fibre
Channel Transceiver
VSC7125
Figure 7: Parametric Measurement Information
Serial Input Rise and Fall Time
Tr
TTL Input and Output Rise and Fall Time
80%
Vih(min)
20%
Vil(max)
Tr
Tf
Tf
Receiver Input Eye Diagram Jitter Tolerance Mask
Bit Time
Amplitude
Eye Width%
Parametric Test Load Circuit
Serial Output Load
Z0 = 75Ω
TTL A.C. Output Load
75Ω
10 pF
VDD – 2.0V
Page 8
 VITESSE SEMICONDUCTOR CORPORATION
741 Calle Plano, Camarillo, CA 93012 • 805/388-3700 • FAX: 805/987-5896
G52121-0, Rev. 4.1
4/23/98
VITESSE
SEMICONDUCTOR CORPORATION
Data Sheet
1.0625 Gbits/sec Fibre
Channel Transceiver
VSC7125
Figure 8: Transmitter Jitter Measurement Method
BERT
Pattern
Generator
DATA
DATA
Trigger
106.25MHz
Digitizing
Scope
1.0625 GHz Clock
RJ
DJ
-K28.7 -K28.7
0011111000 0011111000
VSC7125
TX
REFCLK TX+
TXT0:9
1.0625 Gb/s
Single-Ended Measurement
-K28.5 +K28.5
0011111010 1100000101
Random jitter (RJ) measurements performed according to Fibre Channel 4.3 Annex A, Test Methods, Section A.4.4. Measure
standard deviation of all 50% crossing points. Peak to peak RJ is + 7 sigma of distribution.
Deterministic jitter (DJ) measurements performed according to Fibre Channel 4.3 Annex A, Test Methods, Section A.4.3.
Measure time of all the 50% points of all ten transitions. DJ is the range of the timing variations.
Figure 9: Input Structures
VDD
VDD
+3.3 V
+3.3 V
INPUT
Current
Limit
INPUT
R
INPUT
All Resistors
3.3K
R
GND
REFCLK and TTL Inputs
A
G52121-0, Rev. 4.1
4/23/98
GND
High Speed Differential Input
(RX+/RX-)
B
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VITESSE
SEMICONDUCTOR CORPORATION
Data Sheet
1.0625 Gbits/sec Fibre
Channel Transceiver
VSC7125
DC Characteristics (Over recommended operating conditions).
Parameters
Description
Min
Typ
Max
Units
VOH
VOL
2.4
—
—
V
—
—
0.5
V
1200
—
2200
mVp-p
1200
—
2200
mVp-p
300
—
2600
mVp-p
VIH
VIL
IIH
IIL
Output HIGH voltage (TTL)
Output LOW voltage (TTL)
TX Output differential peakto-peak voltage swing
TX Output differential peakto-peak voltage swing
Receiver differential peak-topeak Input Sensitivity RX
Input HIGH voltage (TTL)
Input LOW voltage (TTL)
Input HIGH current (TTL)
Input LOW current (TTL)
2.0
—
5.5
V
0
—
0.8
V
—
50
500
µA
—
—
-500
µA
—
VIN =2.4V
VIN =0.5V
VDD
Supply voltage
3.14
—
3.47
V
3.3V±5%
∆VOUT751
∆VOUT501
∆VIN1
PD
Power dissipation
—
625
900
mW
IDD
Supply Current
—
190
260
mA
Conditions
IOH = -1.0 mA
IOL = +1.0 mA
75Ω to VDD – 2.0 V
(TX+ - TX-)
50Ω to VDD – 2.0 V
(TX+ - TX-)
Internally biased to Vdd/2
(RX+ - RX-)
Outputs open,
VDD = VDD max
Outputs open,
VDD = VDD max
Note: (1) Refer to Application Note, AN-37, for differential measurement techniques.
Absolute Maximum Ratings (1)
Power Supply Voltage, (VDD).............................................................................................................-0.5V to +4V
DC Input Voltage (PECL inputs) ............................................................................................ -0.5V to VDD +0.5V
DC Input Voltage (TTL inputs) .........................................................................................................-0.5V to 5.5V
DC Output Voltage (TTL Outputs)........................................................................................ -0.5V to VDD + 0.5V
Output Current (TTL Outputs) ................................................................................................................ +/-50mA
Output Current (PECL Outputs)............................................................................................................... +/-50mA
Case Temperature Under Bias .........................................................................................................-55o to +125oC
Storage Temperature.....................................................................................................................-65oC to +150oC
Maximum Input ESD (Human Body Model).............................................................................................. 1500 V
Recommended Operating Conditions
Power Supply Voltage, (VDD)................................................................................................................ +3.3V+5%
Operating Temperature Range ............................................................0oC Ambient to +100oC Case Temperature
Notes:
(1) CAUTION: Stresses listed under “Absolute Maximum Ratings” may be applied to devices one at a time without causing permanent damage. Functionality at or above the values listed is not implied. Exposure to these values for extended periods may
affect device reliability.
Page 10
 VITESSE SEMICONDUCTOR CORPORATION
741 Calle Plano, Camarillo, CA 93012 • 805/388-3700 • FAX: 805/987-5896
G52121-0, Rev. 4.1
4/23/98
VITESSE
SEMICONDUCTOR CORPORATION
Data Sheet
1.0625 Gbits/sec Fibre
Channel Transceiver
VSC7125
Package Pin Descriptions
VSSD
T0
T1
T2
VDDD
T3
T4
T5
T6
VDDD
T7
T8
T9
63
1
61
59
57
55
53
51
49
47
3
45
5
43
7
41
9
39
11
37
13
35
15
17
19
21
23
25
27
29
31
33
N/C
COMDET
VSST
R0
R1
R2
VDDT
R3
R4
R5
R6
VDDT
R7
R8
R9
VSST
N/C
TEST1
EWRAP
TEST2
VSSD
REFCLK
TEST3
EN_CDET
VSSD
TEST4
N/C
VDDD
VDDT
RCLKN
RCLK
VSST
VSSD
VSSD
N/C
TX+
TXVDDP
VDDD
VSSANA
VDDANA
VSSD
VDDD
RX+
VDDP
RXVSSD
VDDD
N/C
N/C
VDDP
Figure 10: Pin Diagram
(Top View)
Table 4: Pin Identification
Pin #
Name
Description
2-4, 6-9,
11-13
T0:9
INPUTS - TTL
10-bit transmit character. Parallel data on this bus is clocked in on the rising edge of
REFCLK. The data bit corresponding to T0 is transmitted first.
22
REFCLK
INPUT - TTL
This rising edge of this clock latches T0:9 into the input register. It also provides the
reference clock, at one tenth the baud rate to the PLL.
62, 61
TX+, TX-
OUTPUTS - Differential PECL (AC Coupling recommended)
These pins output the serialized transmit data when EWRAP is LOW. When EWRAP
is HIGH, TX+ is HIGH and TX- is LOW.
45-43, 4138, 36-34
R0:9
OUTPUTS - TTL
10-bit received character. Parallel data on this bus is clocked out on the rising edges
of RCLK and RCLKN. R0 is the first bit received on RX+/RX-.
G52121-0, Rev. 4.1
4/23/98
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741 Calle Plano, Camarillo, CA 93012 • 805/388-3700 • FAX: 805/987-5896
Page 11
VITESSE
SEMICONDUCTOR CORPORATION
Data Sheet
1.0625 Gbits/sec Fibre
Channel Transceiver
VSC7125
Table 4: Pin Identification
Pin #
Name
19
EWRAP
54, 52
RX+, RX-
31, 30
RCLK,
RCLKN
24
EN_CDET
INPUT - TTL
Enables COMDET and word resynchronization when HIGH. When LOW, keeps
current word alignment and disables COMDET.
47
COMDET
OUTPUT - TTL
This output goes HIGH for half of an RCLK period to indicate that R0:9 contains a
Comma Character (‘0011111XXX’). COMDET will go HIGH only during a cycle
when RCLKN is rising. COMDET is enabled by EN_CDET being HIGH.
18,20,23
TEST1
TEST2
TEST3
INPUT
These signals are used for factory test. For normal operation, tie to VDD.
26
TEST_4
OUTPUT
This signal is used for factory test. For normal operation, leave open.
57
VDDANA
Analog Power Supply
58
VSSANA
Analog Ground
5, 10, 28,
50, 55, 59
VDDD
Digital Logic Power Supply
1, 14, 15,
21, 25,
51, 56
VSSD
Digital Logic Ground
29, 37, 42
VDDT
TTL Output Power Supply
32, 33, 46
VSST
TTL Output Ground
53, 60, 63
VDDP
PECL I/O Power Supply
16,17,27,
48,49,64
N/C
Page 12
Description
INPUT - TTL
LOW for Normal Operation. When HIGH, an internal loopback path from the
transmitter to the receiver is enabled and the TX outputs are held HIGH.
INPUTS - Differential PECL (AC Coupling recommended)
The serial receive data inputs selected when EWRAP is LOW. Internally biased tot
VDD/2, with 3.3KΩ resistors from each input pin to VDD and GND.
OUTPUT - Complementary TTL
Recovered clocks derived from one twentieth of the RX+/- data stream. Each rising
transition of RCLK or RCLKN corresponds to a new word on R0:9.
No Connection. These pins are not internally connected.
 VITESSE SEMICONDUCTOR CORPORATION
741 Calle Plano, Camarillo, CA 93012 • 805/388-3700 • FAX: 805/987-5896
G52121-0, Rev. 4.1
4/23/98
VITESSE
SEMICONDUCTOR CORPORATION
Data Sheet
1.0625 Gbits/sec Fibre
Channel Transceiver
VSC7125
Package Information
64-pin PQFP Package Dimensions
D
Item
10 mm
14 mm
Tolerance
A
2.45
2.35
MAX
A2
2.00
2.00
+.10/-.05
D
13.20
17.20
±.25
D1
10.00
14.00
±.10
E
13.20
17.20
±.25
E1
10.00
14.00
±.10
b
0.22
0.35
±.05
e
0.50
0.80
BASIC
L
0.88
0.88
±.15/-.10
θ
0° - 7°
D1
64
49
48
1
E
E1
16
33
17
32
10o TYP
A
A2
e
100 TYP
0.30 RAD. TYP.
A
STANDOFF
0.25 MAX.
0.20 RAD. TYP.
θ
0.17 MAX.
0.102 MAX. LEAD
COPLANARITY
b
0.25
L
NOTES:
All drawings not to scale
All units in mm unless otherwise noted.
10 x 10 mm Package # 101-266-1
14 x 14 mm Package # 101-262-1
G52121-0, Rev. 4.1
4/23/98
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Page 13
VITESSE
SEMICONDUCTOR CORPORATION
Data Sheet
1.0625 Gbits/sec Fibre
Channel Transceiver
VSC7125
Package Thermal Considerations
The VSC7125 is packaged in either a 10 mm PQFP or a 14 mm PQFP with internal heat spreaders. These
packages use industry-standard EIAJ footprints, but have been enhanced to improve thermal dissipation. The
construction of the packages is as shown in Figure 11.
Figure 11: Package Cross Section
Aluminum Heat Spreader
Plastic Molding Compound
Lead
Epoxy
Bond Wire
Die
Table 5: Thermal Resistance
Symbol
10mm Value
14mm Value
Units
10.5
10
oC/W
Thermal resistance from case to ambient in still air including
conduction through the leads.
53
32
oC/W
θca-100
Thermal resistance from case to ambient with 100 LFM airflow
44
28
oC/W
θca-200
Thermal resistance from case to ambient with200 LFM airflow
39
25
oC/W
θca-400
Thermal resistance from case to ambient with 400 LFM airflow
34
22
oC/W
θca-600
Thermal resistance from case to ambient with 600 LFM airflow
31
20
oC/W
θjc
θca
Description
Thermal resistance from junction to case
The VSC7125 is designed to operate with a junction temperature up to 110oC. The user must guarantee that
the temperature specification is not violated. With the Thermal Resistances shown above, the 10x10mm PQFP
can operate in still air ambient temperatures of 53oC [53oC=110oC-0.9W*(10.5oC/W+53oC/W)] while the
14x14 PQFP can operate in still air ambient temperatures of 73oC [73oC=110oC-0.9W*(10oC/W+32oC/W)]. If
the ambient air temperature exceeds these limits then some form of cooling through a heatsink or an increase in
airflow must be provided.
Moisture Sensitivity Level
This device is rated with a moisture sensitivity level 3 rating. Refer to Application Note AN-20 for appropriate handling procedures.
Page 14
 VITESSE SEMICONDUCTOR CORPORATION
741 Calle Plano, Camarillo, CA 93012 • 805/388-3700 • FAX: 805/987-5896
G52121-0, Rev. 4.1
4/23/98
VITESSE
SEMICONDUCTOR CORPORATION
Data Sheet
1.0625 Gbits/sec Fibre
Channel Transceiver
VSC7125
Ordering Information
The part number for this product is formed by a combination of the device number and the package style:
VSC7125xx
Device Type:
VSC7125: 1.0625 Gbps Transceiver
Package Style (64-pin)
QN: 14x14mm PQFP
QU: 10x10mm PQFP
Marking Information
The package is marked with three lines of text as shown below (QU Package):
Pin Identifier
VITESSE
VSC7125QU
Part Number
Date Code
####
AAAA#
Package Suffix
Lot Tracking Code
Notice
Vitesse Semiconductor Corporation reserves the right to make changes in its products specifications or
other information at any time without prior notice. Therefore, the reader is cautioned to confirm that this
datasheet is current prior to placing any orders. The company assumes no responsibility for any circuitry
described other than circuitry entirely embodied in a Vitesse product.
Warning
Vitesse Semiconductor Corporation’s product are not intended for use in life support appliances, devices or
systems. Use of a Vitesse product in such applications without written consent is prohibited.
G52121-0, Rev. 4.1
4/23/98
 VITESSE SEMICONDUCTOR CORPORATION
741 Calle Plano, Camarillo, CA 93012 • 805/388-3700 • FAX: 805/987-5896
Page 15
VITESSE
SEMICONDUCTOR CORPORATION
1.0625 Gbits/sec Fibre
Channel Transceiver
Page 16
 VITESSE SEMICONDUCTOR CORPORATION
741 Calle Plano, Camarillo, CA 93012 • 805/388-3700 • FAX: 805/987-5896
Data Sheet
VSC7125
G52121-0, Rev. 4.1
4/23/98